<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="../js/jquery-1.11.3.js"></script>
</head>
<body>
<li>aa</li>
<li>bb</li>
<li>cc</li>
<script>
    $("li").each(function(i){
        console.log(i);
        console.log(this);
    });

    var a = ['aa','bb','cc'];
    $.each(a,function(k,v){
        console.log(k,v)
    })
</script>
</body>
</html>